Oceanography index

by Dr J Floor Anthoni (2000)
www.seafriends.org.nz/oceano/index.htm
(best viewed in a window as wide as a page. Open links in a new tab.)

Oceanography is the science that studies the
world's oceans, its waters and depths, how they move and how they play
a part in the whole of our planet. In this section you can learn more about
the sea and how it affects life. The sea is not just a big bucket of salty
water, but a living system that controls many aspects of this planet, and
thus your life too. This section forms the basis for understanding how
our planet works.

Oceanography covers all we know about the sea,
its formation, geology, mineralogy, extraction, fisheries, biology and
much more. For this web site we have made a conscious selection. If you
are in a hurry, read this first. (located
on this page) (3 pages)

The world's oceans cover more than 70% of the Earth's surface. At places
they are as deep as the tallest mountains. Read more about their size,
surface distribution, origin, evolution, features, crust, tectonic plate
movement and more. (14 pages)

The salt water has important properties for life in the seas, properties
that influence the circulation of the ocean water. Read more about its
temperature, seasons, density and productivity. (8 pages)

Waves are caused by the wind blowing over the ocean's surface. They
promote the exchange of gases between the ocean and the atmosphere and
bring water movement to coastal habitats. They are responsible for the
shape of our coasts and the formation of dunes and beaches. In this chapter
you'll learn how waves work and how they relate to wind. (7 pages)

Tsunamis and mega tsunamis are special waves, and so are seiches, bores
and internal waves. Special attention is paid to the kind of damage waves
cause to the land and the underwater seascape. (7 pages)

The tides are caused by the rotation of the Earth in the presence of
the gravitational pull of moon and sun. Often interpreted as a water 'bulge'
travelling around the globe, being balanced by an equal bulge on the other
side, recent discoveries have made this simplified concept much more interesting.
(5 pages)

Waves and tides cause currents that see-saw to and fro but the large
ocean basins have currents that flow mainly in one direction. Such currents
cause upwellings of nutrients from the deep, influence the weather and
bring about cyclical changes in coastal seas. (16 pages)

Extreme events such as storms, hurricanes and tsunamis have major effects
on people living by the sea. They turn a peaceful ocean into a devouring
monster. They make a difference to dunes and beaches and the underwater
environment. (6 pages)

As carbon dioxide levels are rising in air, it is feared that the oceans
will become more acidic, with disastrous consequences for marine life.
What is the story? What do the facts show? Is this another scare scam?
(large, detailed and important)

The world's climates are changing, thought to be related to global
warming. The world appears to be warming because of human emissions, is
the consensus, but many scientists disagree. This large chapter views all
issues from a wide perspective, to foster understanding. Learn about climate
step by step. (140 pages)

Books and references (on this page)
Valuable Internet links (on this page)
Note that his section has been mirrored by POEMS, Practical
Ocean Energy Management Systems (www.poemsinc.org)
in the USA. They promote research into generating power from the oceans.
Visit their link page for more info on oceanography and ocean energy.

Note! for best printed results, set your page up with a left
margin of 1.5cm (0.6") and right margin of 1.0cm (0.4"). Read tips
for printing.The whole section covers about 1.7MB, including text,
drawings and photographs.-- home -- site
map -- Rev:20000823,20010428,20030130,20060423,20070718,20091115,

IntroductionOceanography covers all we know about the sea,
its formation, geology, mineralogy, extraction, fisheries, biology and
much more. Knowledge about our oceans was first acquired by those
who used it and plied its waters. Although they provided for food, the
oceans were largely seen as a strategic obstacle, hindering the trading
of goods and the migrating of people. It is only recently that the oceans
have been studied scientifically. Ironically, a large motivation came from
the navies of seafaring countries. The oceans are truly difficult to lay
bare to scientific scrutiny. They are so large, rough and deep. Consequently,
there remains much to be discovered, but already the amount we know is
too much to be included in this web site.

The oceans are not just big buckets of water but a large and complex
system of geological, physical, chemical and biological factors that have
a decisive influence on the course of the terrestrial world, and thus also
our lives. The oceans are perhaps the only habitat, large enough that we
will not be able to change sufficiently to destroy its functioning, although
we seem intent on doing so, and on the land we almost certainly will. The
oceans may thus hold the key to our salvation. We have included in this
large section everything you need to know to be an effective conservationist,
understanding the big picture, life on this planet, marine life and the
problems caused by humanity.

The first chapter looks at the beginning of Earth and ocean and how
they evolved together. The movements of tectonic plates has shaped the
continents and distributed their inhabiting species. Climate has changed
dramatically, yet becoming more stable overall.

The second chapter looks at ocean properties like temperature, salinity
and productivity. These are important for understanding ocean currents
and fishing. The next chapter looks at waves and examines how they work.
Waves shape the coasts and can damage organisms in the sea. Tsunamis are
very slow waves that can travel vast distances, where they can cause massive
coastal damage. Internal waves are mysterious water movements inside a
body of water and invisible from above. The next chapter deals with another
wave, the tide. It is an often misunderstood phenomenon.

The currents chapter looks at the atmosphere first and how sunlight
passes through to warm the surface. On its way, various atmospheric gases
filter the sunlight and also Earth's outgoing radiation. More about this
will be discussed in the chapter on global warming. Solar radiation varies
with latitude, but particularly with depth in the ocean. Heat is distributed
from the warm tropics to the cold poles by means of air and water circulation.
A major influence on the movement of air and water is the Coriolis force,
explained in detail. The chapter ends with deep water currents.

Where the sea meets the land, often dunes and beaches are formed. In
the chapter about these, it is explained how beaches and dunes form and
how they interact with wind and waves. Examples of beaches are shown.

The chapter about why dunes and beaches are disappearing, is my own
work, in which I challenge scientists and society to look at the problem
in a different way. I've discovered a large gap in coastal science, where
hard data about the most important factors affecting beaches and dune systems,
is simply not available. It is a must-read for everyone working with, living
by, or just enjoying sandy beaches.

Storms, particularly cyclones (hurricanes) have a major influence on
our coasts and thus the beaches. This chapter shows why.

The chapter about why New Zealand is such a special country, was placed
here because it links in with many of the factors discussed in oceanography.
It shows how NZ's geographic location and tectonic past has made it unique
in the world. Discovered by humans only recently, it is more sensitive
to human actions than earlier discovered countries are. NZ's agricultural
economy exploits the renewable solar energy but brings unique problems.
It is knowledge that every Kiwi should learn at school.

I have deliberately left out the water, carbon and nutrient cycles because
these will be dealt with in the section about plankton. The El Nino climate
oscillation will be discussed in the section on global warming. The oceanography
of tideways (estuaries) will be treated in the section on habitats.
Several interesting tables have been put together with information
gleaned from many sources. The periodic table of elements introduces the
reader to the chemical elements on this planet and the structure of atoms.
The reader is introduced to basic chemistry and radioactive decay.
The table of the abundance of elements shows their journey through
the composition of the universe, our solar system, fresh and salt water
and eventually of plants and animals. Deficiency syndromes are also shown.